1. Field of the Invention
The present invention relates to a method for making a stackable package, and more particularly to a method for making a stackable package having a redistribution layer and a through via.
2. Description of the Related Art
FIG. 1 shows a cross-sectional view of a conventional stackable package. The conventional stackable package 1 comprises an interposer 10 and a chip 20. The interposer 10 comprises a body 11, a plurality of through vias 12, a plurality of conductive traces 13, a plurality of pads 14 and a plurality of solder balls 15. The body 11 has a first surface 111 and a second surface 112. The through vias 12 penetrate through the body 11, and are exposed to the first surface 111 and the second surface 112. The conductive traces 13 are disposed on the first surface 111 of the body 11, and electrically connected to the through vias 12. The pads 14 are disposed on the second surface 112 of the body 11, and electrically connected to the through vias 12. The solder balls 15 are disposed on the pads 14. The chip 20 is disposed on the interposer 10. The chip 20 comprises a plurality of chip pads 21 and a plurality of bumps 22. The bumps 22 are disposed between the chip pads 21 and the conductive traces 13, and the chip 20 is electrically connected to the interposer 10 by the bumps 22.
The conventional stacked package 1 has the following disadvantages. The chip 20 of the conventional stacked package 1 is electrically connected to exterior elements by the interposer 10. However, the interposer 10 increases the thickness of the product, and the manufacturing processes of the interposer 10 is too complicated, so that the manufacturing cost is increased. Moreover, the gap between the bumps 22 of the chip 20 is too small, so that an underfill (not shown) is difficult to be formed therein to encapsulate the bumps 22.
Therefore, it is necessary to provide a method for making a stackable package to solve the above problems.